Tie rod for concrete wall forms



Nov. 3, 1953 B. HILLBERG 2,657,449

- TIE ROD FOR CONCRETE WALL FORMS Filed March 2, 1949 2 Sheets-Sheet lB. HILLBERG Nov. 3, 1953 Filed Marc Patented Nov. 3, 1953 UNITED STATESPATENT OFFICE Bror llillberg, Qh-icago, 111., assignor to SuperiorConcrete Accessories, Inc., Chicago, 111., a corr ation of IllinoisApplication ,March Z, 1949, Serial No. 79,141 cci i s. (01. 25-131) Thepre ent invention r lates en al y to ti rods for use in concreteconstruction. More par,- t l rly the invent on relates to that WPBj-fl.ti rod-which is designed f r us wi h a pai of spaced apart, verticallyextending wall forms having opposi ely disposed :holes therein an wedgevariety attaching .devices outwards of the holes, is adapted when in useto extend horizontally and :have its ends project through the holes inthe forms and attached to the attaching devices, has stop-formingwashers directly inwards of its .ends forenga-gement .withthe innersurfaces of the hole defining portions of the terms, embodies atpredetermined distances inwards of the washers 'breakeoff points andinwards of the break-oif-poi-nts flats, serves while in its operativeposition and in connection with pouring of con-- crete between the formsto hold the forms against inward andioutwarddisplacement, and is adaptedafter hardening of'the concrete, release of the attaching devices andremoval or .dismantlement of the forms, to haveits projecting ends bentat substantially right angles and then turned or twisted inorder tobreak or sever them from the central portionof the rod at thebreak-off.points within the .side faces of the concrete wall.

In connection'with the fabrication .ofa {tie rod of this type it hasheretofore been proposed to utilize a rod formedof steel of aicertainhardness and after formationof the break-off points and flats bysuitable dies, to mount conical washers of harder steel on the rodat theproper locations ouwards of the break-off points. After mounting orproper positioning of the washers the latter are flattened .in anysuitable manner :inorder to cause such contractionof the inner marginsthat the washers-become interlocked with the .rod. in practice it hasbeen found that a tie rod that is formed or fabricated in accordancewith the aforementionedtechnique or methodis subject to severalobjections. In the first place, flattening of the conicalwashers-results in the corners .of the inner marginsof .the washers sodigging into the adjacent portions oftherodthat they rupture or severthesteel fibers of the rod to such anextent that when the ends of .therod are bentand twisted they break off adjacent-the washers instead ofat the break-off .points. In the event that the ends ofthettie-rodibreakcif at the stopforming washers instead of attheinwardly disposed break-oif points the portions of the rod betweenthe actualbreak-offs and the -,in tended break-01f points are eitherleft in place or .remov d- ,I left in p ac uc po tion becaus the outerext m i h re a flush wit the 2 side faces of the concrete wall, areunsightly and in connection with rusting thereof discolor the concrete.If the portions are removed difiiculty is encountered in connection withthe removal operation and itis generally necessary to deface or chipaway the concrete around the portions. Another objection .to a tie rod,the washers of which are mounted in place as heretofore indicated, isthat the washers grip the adjacent portions of the tiered withsuch forceor so tightly that when the projecting endspf the rod are bent at rightangles and turned in connection with the break-off operation the washersturn with the rod ndsnd hen spe e conc e e u t washers, thusnecessitatingacostly patching operation.

One of the principal objects of this invention is to provide atierodwhich is an improvement upon, and-eliminates the objectionsof,previously designed tie r-odsan d ischaracterized by the fact that thestop-forming washers are fi-at whenoriginally mounted on the rod andhave the inner margins thereof so compressed .by the action of suitabledies that they are inwardly extruded in such manner as to form in theadjacent portions of the rod shallow annulargrooves which are of arcuatecrosssectionand are so interlocked with the extruded portions of theinner margins of the washers thatthe washers areheld againstlongitudinal or axialdisplacement with respect to the rod, while at thesame time they permit the rod, inconnection with turning of theprojecting ends thereof, to rotate relatively thereto. By having thewashers [mounted on the rod .in this manner there-is no cutting orrupture of the fibers of the rod-that-are within the washers and hencein connection with bending and turning of the project.- ing ends of therod the ends break on" at the break-off points instead of at thewashers. In addition, the projecting ends of vthe rod in connection withbreak-off turn relatively to the washers and hence the washers do noteffect spalling of the portions of the concrete .in which they areembedded.

Another object of the invention is to provide a tie rod which isgenerallyof new and improved construction, efiectively a'nd eflicientlyfulfills its intended purpose and is capable .offlbeing .projducedatalowcost. i

Qther objects of-the invention and the various advantages andcharacteristics of the presentltie rod will be apparent from aconsideration of the following detailed description.

The inventionconsists in the several novel tures wn e l eres ite s iieti an a 3 more particularly defined by claims at the conclusion hereof.

In the drawings which accompany and form a part of this specification ordisclosure and in which like numerals of reference denote correspondingparts through the several views:

Figure l is a side view of a tie rod embodying the invention; I

Figure 2 is a view, partly in side elevation and partly in verticalsection, showing the tie rod in operative or connected relation with apair of spaced apart, vertically extending wall forms having oppositelydisposed holes therein for re ceiving the ends of the tie rod and wedgevariety attaching devices outwards of the holes for con- 4 nection tothe outer projecting extremities of the tie rod;

Figure 3 is a view partly in side elevation and partly in sectionshowing the tie rod of Figure 2 after removal of the wall formsfollowing hardening or solidification of the concrete, and illustratingthe manner in which the projecting ends of the rod are bent at rightangles and then turned to effect break-off at the break-oil points thatare inwards of the stop-forming washers;

Figure 4 is an enlarged fragmentary longitudinal section illustrating indetail the construction and design of the stop-forming washers on therod and showing the manner in which they are mounted on the rod and sointerlocked there- :11:

with that they are held against longitudinal or axial displacement withrespect to the rod while at the same time permitting the ends of therods to turn relatively thereto in connection with a break-offoperation;

Figure 5 is a plan view showing the coacting washer compressing diesbefore they are actuated to extrude the inner margin of one of thewashers so as to cause it to form in the adjacent portion of the rod ashallow annular groove of arcute cross section;

Figure 6 is a horizontal section showing the coacting dies after theyhave been actuated so as to extrude by compression the inner margin ofthe stop-forming washer therebetweemand Figure 7 is a plan view showingthe dies in retracted open position after a washer compressingoperation.

The tie rod which is shown in the drawings constitutes the preferredform or embodiment of the invention. It is designed and adapted for usein connection with a pair of spaced apart, vertically extending wallforms 8 and serves, in conjunction with a pair of wedge varietyattaching devices 9, as hereinafter described more in detail, to holdthe forms against inward and outward displacement during pouring ofconcrete between the forms for purposes of forming a vertical wall. Theforms 8 are of standard or conventional construction and each, as shownin Figure 2, consists of a rectangular panel In and a rectangularreenforcing frame H on the outer side of the panel. The frames II of theforms 8 have pairs of horizontal, spaced apart intermediate crosspiecesI2 and these are adapted to be positioned in horizontal alignment whenthe forms are in their operative or concrete wall forming position. Theholes I3 are formed in the panels I0 between the central portions of thecrosspieces I2. When the tie rod is in its operative position withrespect to the forms 8 its ends project through the holes I3 and betweenand beyond the frame crosspieces I2 as shown in Figure 2 of thedrawings. As well understood in the art, the forms 8 are arranged in anopposed laterally spaced, upstanding position preparatory to pouring ofconcrete therebetween. In connection with positioning of the forms theends of the tie rod are inserted through the holes I3 in the panels IIIof the forms. After insertion of the ends of the tie rod through theholes the wedge variety attaching devices 9 are applied so asoperatively to connect the tie rod to forms. As soon as the devices 9are connected to the extremities of the tie rod the tie rod serves tohold the forms 8 in proper position. Formation of a concrete wall isaccomplished by pouring concrete between the two forms. After hardeningor solidification of the concrete the attaching devices 9 are withdrawnfrom the extremities of the tie rod and the forms are removed from theconcrete wall by shifting them outwards. After removal or dismantlementof the forms the projecting ends of the tie rod are bent at right anglesand turned in order to break or sever them from the central portion ofthe rod at points inwards of the side faces of the concrete wall.

The tie rod is formed of comparatively hard steel to the end that itpossesses the desired tensile strength. It is designated in the drawingby the reference numeral I4 and for the most part is circular in crosssection. Preferably the tie rod is formed of inch steel stock, thecarbon content of which is approximately of 1%. As shown in Figure l ofthe drawings the tie rod is provided with heads I 5, stop-formingwashers I6 inwards of the heads, break-off points I? inwards of thewashers, and flats I8 inwards of the breakoff points. The heads I5 areformed at the extremities of the tie rod I4 and when the tie rod is inits operative position are located small distances outwards of thecrosspieces I2 of the form frames II. They are slightly smaller than theholes I3 in the panels I!) and, in connection with use of the tie rod,are adapted to abut against the outer surfaces of the attaching devices9, as shown in Figure 2. The attaching devices 9 are downwardly taperedand have longitudinal slots therein. They are adapted after applicationto the outer ends of the rods to be driven downwards between the headsI5 and the frame crosspieces I2 and serve to clamp the forms against thestop-forming washers I6. The latter, as described hereafter, are mountedon the rod I4 against longitudinal or axial displacement relativelythereto and serve when the tie rod is in its operative position toprevent inward movement of the forms 8. The break-off points I! arelocated but comparatively small distances inwards of the stop-formingwashers I6 and are in the form of opposed pairs of notches. When theprojecting ends of the tie rod are bent at right angles and then turnedor twisted after removal of the forms 8 from the concrete wall theybreak off at the break-off points II. The flats I8 are formed on thecentral portion of the tie rod I4, i. e., the portion of the rod that isembedded in the concrete and serve to prevent rotation of the centralportion of the tie rod in the concrete when the ends of the rod areturned or twisted for break-off purposes. It is contemplated that thebreak-off points and flats will be formed before the stop-formingwashers I6 are mounted on the rod as described hereafter.

The washers I6 are formed of harder steel than the tie rod proper.Preferably they are formed of steel stock of 14 gauge and with a carboncontent of approximately of 1%. The washers before mounting on the rodare flat and have an internal diameter slightly greater than the diudedportions 322 inwards of the grooves. Due to the manner in which theinner margins of the washers are compressed between the dies {9 and 120the extruded portions 22 are segmental in cross section. in connectionwith thecom- "pressing operation the "extruded portions 22 compress theadjacent portionsofthe tie rod proper seas .to form therein annulargrooves 23 which are of arcuatecro'ss' section and coact with theextruded portions 22 to .hold the washers I6 against longitudinal oraxial displacement with respect to the rod. Due to the cross sectionalshape sof the extruded portions 22 and the-maniner in which suchportions are formed,;-tl ie steel fibers of the portions of the rod thatare within the washers are not cut or ruptured and hence auiacent thewashers the rod is :not so weakened that connection with turning of theprojecting .iemisnf the rod it will break on at the washers in- The gripbe- 1 stead of the break-01f points II. tween the extruded portions 22of the Washers and the adjacent groove portions of the rod is such thatthe washers and rod are normally not relatively rotatable but when theends of the rod are turned for break-off purposes such ends will turnrelatively to the washers and hence not cause the washers to rotate andcause or effect spalling of the portions of the concrete wall in whichthey are embedded. The annular grooves 2I which are formed in connectionwith compressing of the inner margins of the washers I6 are inwardlytapered and extend approximately half way through the washers. As bestshown in Figure 4 of the drawings the grooves 2| are trapezoidal incross section.

The dies I9 and which are utilized to compress the inner margins of thewashers I6 into interlocked relation with the adjacent portions of therod are disposed one opposite the other as well as in spaced apartrelation, as shown in Figures 5, 6 and 7. The die I9 is a split die andconsists of a pair of complemental, oppositely disposed sections 24. Thelatter are movable to and from one another and have in the opposed facesthereof full length grooves which are semicircular in cross section andwhen the sections 24 are in abutment with one another define acylindrical hole through which the tie rod is adapted to extend. Thefaces of the sections 24 of the split die I9 that are opposite the die20 are fiat and coplanar. The die 20 is mounted in a tubular guide 26 toslide to and from the split die I9. It has a centrally disposed, openended, rod-receiving hole 21 in coaxial relation with the grooves 25 inthe opposed faces of the sections 24 of the die I 9 and embodies on theend face thereof that is adjacent the die I9 an annular rib 28. This ribis disposed directly outwards of the adjacent end of the hole 21 and isoutwardly tapered so that it is trapezoidal in cross section. Theportion of the outer end face of the die 20 that is outwards of the rib28 is fiat. as shown in Figure 6.

In connection with mounting of one of the washers on the tie rod proper,the washer in truly fiat form is mounted between the two dies I9 and 20in such manner that its hole is in centered relation with the hole inthe die I9 and the hole '21 in the die '20, it being understood thatinsertion of the washer into place or position occurs while-the sections'24 ot the-die 1 9 are-m abutment, as shown in Figure After-properposition-mg of the washer one end QT the tiered I4 is inserted throughthe hole in the die F9, the hole in the'washer and the hole 2-! in thedie' zil. As soon as one end of the rod is -inserted to the properextent the movable die 29 is slid towards the 'die I9 until the annularrfib '23 on the*o uter end thereoffbe'comes fully embedded in the innermargin of" the washer. In connectionwith -emfbedmentof the rib the innermargin 'jo'f the washer 'is 'deformed by compression so that it embodiesthe annular inwardly tapered groove and the inwardly extending extrudedportion 22. Such portion, in connection with formation thereof, isforced into the 'adiiacentlportion of the rod and "forms the shallowannular groove which, as heretofore pointed out, coacts with theextruded portion to hold the washer against axial displacement withrespect to the rod; hitter deformation of the inner margin of the washerthe movable die 20 is retracted and these'ctioi-is '24 of the die I9 arespread apart or separated. Thereafterthe rod with thewasher mounted "onone end thereof is removed from the two dies I9 and 20. The other washeris mounted on the other end of the tie rod in precisely the same manner.After mounting of the two washers on the rod the heads I5 are formed onthe extremities of the rod.

The herein described tie rod is characterized by the fact that due tothe particular manner in which the stop-forming washers are mounted onthe rod proper the ends of the rod, in connection with a break-offoperation, will break off at the break-off points I! instead of withinthe washers. It is further characterized by the fact that although thewashers are fixedly held against longitudinal or axial displacement withrespect to the rod, the ends of the rod during twisting for break-offpurposes are permitted to turn relatively to the washers and hence thereis no likelihood of the washers spalling the portions of the concrete inwhich they are embedded. Due to the manner in which the washers aremounted on the rod the tie rod as a whole may be manufactured orfabricated at an extremely low cost and eifectively and efflcientlyfulfills its intended purpose.

The invention is not to be understood as restricted to the detail-s setforth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

I-iaving thus described the invention what I claim as new and desire tosecure by Letters Patent is:

1. As a new article of manufacture, a tie rod designed to hold a pair ofconcrete wall forms in spaced apart relation, formed of a piece of metalof circular cross section and certain hardness, having a portion thereofinwards of one of its ends weakened to form a break-off point, andembodying at a comparatively small distance outwards of the break-offpoint an originally fiat circular form-engaging washer formed of hardermetal and having at one side thereof and spaced a small distance fromits inner periphery a concentric die-formed inwardly tapered trulycontinuous annular groove whereby the portion of the washer inwards ofthe groove is extruded inwards and is caused to be of shallow segmentalcross section and to form in the contiguous portion of the rod withoutrupture of the fibers thereof or weakening it to the same extent as theweakened portion of the rod, a shallow correspondingly shaped trulycontinuous annular groove by which the washer is so interlocked with therod that it is positively held against displacement lengthwise of therod while at the same time it grips the rod tightly but permits the rodto turn relatively to it in response to application of a comparativelyheavy turning force to the rod while the washer is held againstrotation.

2. As a new article of manufacture, a tie rod designed to hold a pair ofconcrete wall forms in spaced apart relation, formed of a piece of steelof circular cross section and certain hardness, having spaced apartportions of its central part weakened to form break-off points, andembodying at comparatively small distances outwards of the break-offpoints but inwards of its extremities originally flat circularform-engaging washers formed of harder steel and having at one sidethereof and spaced a small distance from their inner peripheriesconcentric die-formed inwardly tapered truly continuous annular grooveswhereby the portions of the washers inwards of the grooves are extrudedinwards and are caused to be of shallow segmental cross section and toform in the contiguous portions of the rods without rupture of thefibers thereof or weakening them to the same extent as the weakenedportions shallow correspondingly shaped truly continuous annular groovesby which the washers are so interlocked with the rod that they arepositively held against displacement lengthwise of the rod while at thesame time they grip the rod tightly but permit the rod to turnrelatively to them in response to application of a comparatively heavyturning force to the rod while the washers are held against rotation.

BROR HIILBERG.

References Cited in the file of this patent UNITED STATES PATENTS

